By the end of the Civil War, between one-third and one-half of all U.S. paper currency in circulation was counterfeit. On July 5, 1865, the Secret Service was created under the U.S. Treasury Department. In less than a decade, counterfeiting was sharply reduced. In the past ten years the breakdown of denominations counterfeited has changed dramatically. The total of known $50 and $100 notes counterfeited has increased by sixty percent. The total number of fifty and one hundred dollar notes passed and seized in 1980 was 777,957. The total number of fifty and one hundred dollar notes passed and seized in 1990 was 1,240,840. In 1990, thirty-six percent of the dollar value of known counterfeit currency passed in the U.S. was produced overseas, particularly in Colombia, Italy, Hong Kong, the Philippines and Bangkok. One hundred and thirty-nine domestic counterfeit operations and eighteen foreign counterfeit operations were suppressed in 1990.
Source: Federal Bank of San Francisco